Which cologne or perfume makes big cats go absolutely wild? Researchers refuse to say, because they don't want humans testing it out and encroaching on the natural habitat of wild cats any more than they already are. But Calvin Klein's cologne Obsession for Men is certainly a favorite.

Cats of all sizes are extremely sensitive to smell--it's one way they communicate. And a whiff of this Calvin Klein cologne made some big cats behave as though they've just been sprinkled with catnip. Watch the video from National Geographic.

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